I am now amending my 2018 tax return to remove a w-2 off of there. I have not received my refund yet from the original tax return I filed, but I can still amend right?

You should wait for the original to complete processing, just in case if IRS changes anything on the original the amended wont be correct either.

It's best to wait to file the amended return until you receive the refund from the original tax return, in case the IRS makes any unexpected changes in your tax return or refund. Your amended return assumes that you received the original refund. You want to make sure that that's true. It's also possible that the IRS will notice that there's a W-2 in your original return that doesn't belong there, and make the correction.